3x(x+2)=x-18

Solution for 3x(x+2)=x-18 equation:

Simplifying
3x(x + 2) = x + -18

Reorder the terms:
3x(2 + x) = x + -18
(2 * 3x + x * 3x) = x + -18
(6x + 3x2) = x + -18

Reorder the terms:
6x + 3x2 = -18 + x

Solving
6x + 3x2 = -18 + x

Solving for variable 'x'.

Reorder the terms:
18 + 6x + -1x + 3x2 = -18 + x + 18 + -1x

Combine like terms: 6x + -1x = 5x
18 + 5x + 3x2 = -18 + x + 18 + -1x

Reorder the terms:
18 + 5x + 3x2 = -18 + 18 + x + -1x

Combine like terms: -18 + 18 = 0
18 + 5x + 3x2 = 0 + x + -1x
18 + 5x + 3x2 = x + -1x

Combine like terms: x + -1x = 0
18 + 5x + 3x2 = 0

Begin completing the square.  Divide all terms by
3 the coefficient of the squared term: 

Divide each side by '3'.
6 + 1.666666667x + x2 = 0

Move the constant term to the right:

Add '-6' to each side of the equation.
6 + 1.666666667x + -6 + x2 = 0 + -6

Reorder the terms:
6 + -6 + 1.666666667x + x2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + 1.666666667x + x2 = 0 + -6
1.666666667x + x2 = 0 + -6

Combine like terms: 0 + -6 = -6
1.666666667x + x2 = -6

The x term is 1.666666667x.  Take half its coefficient (0.8333333335).
Square it (0.6944444447) and add it to both sides.

Add '0.6944444447' to each side of the equation.
1.666666667x + 0.6944444447 + x2 = -6 + 0.6944444447

Reorder the terms:
0.6944444447 + 1.666666667x + x2 = -6 + 0.6944444447

Combine like terms: -6 + 0.6944444447 = -5.3055555553
0.6944444447 + 1.666666667x + x2 = -5.3055555553

Factor a perfect square on the left side:
(x + 0.8333333335)(x + 0.8333333335) = -5.3055555553

Can't calculate square root of the right side.

The solution to this equation could not be determined.